Object-Spaced Normalmapping with Arnold

[starcow]

He Guys
I'm looking for a method to use object-spaced normalmaps in combination with the Arnold-Renderer.
My method in Mental Ray was to use the Color_to_Vector Node with the Normalmap-Option and Plug this directly into the Meterial.
This method seems no longer working under Arnold.

Is there a alternativ way to use object-spaced normalmaps in Arnold?

Cheers

- starcow